1. Field of the Invention
The present invention relates to a mounting structure of a high pressure fuel pump for a gasoline direct injection engine, and more particularly, to a high pressure fuel pump for a gasoline direct injection engine which is equipped with a high pressure fuel pump on the outer side of a cam carrier.
2. Description of Related Art
In general, gasoline direct injection engines that directly inject gasoline into the combustion chamber, using a injector, need a high pressure pump to increase the low pressure (about 4 bar) of fuel supplied from a fuel tank to high pressure (about 150-200 bar).
In the related art, a high pressure fuel pump 1 was directly fastened to a cylinder head cover 2, as shown in FIG. 1, or an adaptor, which is a separate part, was mounted on cylinder head cover 2 and high pressure fuel pump 1 was combined with the adaptor.
Further, in the structure having high pressure fuel pump 1 mounted on cylinder head cover 2, as described above, high pressure fuel pump 1 protruded vertically from the top of cylinder head cover 2.
However, that structure mounting high pressure fuel pump 1 had a problem that high pressure fuel pump 1 vertically protrudes upward from the top of cylinder head cover 2, entire height of the engine room increases and accordingly this is disadvantageous in design and layout of the vehicle hood.
Further, the structure had a problem that when high pressure fuel pump 1 is mounted on cylinder head cover 2, the space inside cylinder head cover 2 is reduced by high pressure fuel pump 1 and accordingly it becomes difficult to dispose baffles for forming a blow-by gas ventilation system inside cylinder head cover 2.
In particular, in a two-cylinder engine, when high pressure fuel pump 1 is mounted on cylinder head cover 2, it is impossible to disposed baffles inside cylinder head cover 2.
Further, high pressure fuel pump 1 includes tappets, such as roller and pistons which are operated by power transmitted through a cam and the tappets should be lubricated for smooth operation, such that oil for lubrication is supplied from the cylinder head.
However, when high pressure fuel pump 1 is mounted on cylinder head cover 2, as in the related art, the oil line for supplying oil from the cylinder head is elongated, and as the oil line is elongated, it is difficult to form the oil line and a problem may occur in sealing.
Further, when high pressure fuel pump 1 is mounted by an adaptor, which is a separate part, the cost and weight increase and the assembly cycle increases, such that it is disadvantageous in terms of productivity.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.